Specificities of Caenorhabditis elegans and human hairpin binding proteins for the first nucleotide in the histone mRNA hairpin loop
Specificities of Caenorhabditis elegans and human hairpin binding proteins for the first nucleotide in the histone mRNA hairpin loop
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DOI：
10.1017/s135583820000056x
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发表时间：
2000-11-01
期刊：
影响因子：
4.5
通讯作者：
Müller, B
中科院分区：
文献类型：
--
作者：
Michel, F;Schümperli, D;Müller, B
动物复制依赖性组蛋白mRNA的3'端是通过高度保守的RNA发夹下游的初级转录物的核酸内切切割形成的。发夹结合蛋白（HBP）与该RNA元件结合，并参与组蛋白RNA 3'加工。在人HBP中鉴定了与其它已知RNA结合基序没有相似性的类似于73个氨基酸的最小RNA结合结构域（RBD）[Wang Z-F等，Genes & Dev，1996，10：3028-3040]。人和秀丽隐杆线虫RBD之间的一级序列同一性为55%，而全长蛋白的一级序列同一性为38%。我们分析了秀丽隐杆线虫和人HBP和发夹之间的差异是否反映在RNA结合的特异性中。梭线虫HBP和它的RBB只识别它们的同源RNA发夹，而人HBP或RED可以结合哺乳动物和C.优雅的发夹。秀丽隐杆线虫HBP的这种选择性主要由环中的第一个核苷酸介导，即C中的C。通过将人RED中的氨基酸转化为相应的秀丽隐杆线虫残基，在后者偏离共有序列的地方，我们可以鉴定两个有助于选择发夹环的第一个核苷酸的氨基酸片段。
The 3' ends of animal replication-dependent histone mRNAs are formed by endonucleolytic cleavage of the primary transcripts downstream of a highly conserved RNA hairpin. The hairpin-binding protein (HBP) binds to this RNA element and is involved in histone RNA 3' processing. A minimal RNA-binding domain (RBD) of similar to 73 amino acids that has no similarity with other known RNA-binding motifs was identified in human HBP [Wang Z-F et al,, Genes & Dev, 1996, 10:3028-3040]. The primary sequence identity between human and Caenorhabditis elegans RBDs is 55% compared to 38% for the full-length proteins, We analyzed whether differences between C, elegans and human HBP and hairpins are reflected in the specificity of RNA binding. The C. elegans HBP and its RBB recognize only their cognate RNA hairpins, whereas the human HBP or RED can bind both the mammalian and the C. elegans hairpins. This selectivity of C, elegans HBP is mostly mediated by the first nucleotide in the loop, which is C in C. elegans and U in all other metazoans, By converting amino acids in the human RED to the corresponding C, elegans residues at places where the latter deviates from the consensus, we could identify two amino acid segments that contribute to selectivity for the first nucleotide of the hairpin loop.